A circuit board including electronic components such as integrated circuit (IC) chips mounted on a substrate via an anisotropic conductive film (ACF) containing conductive particles has been known. A chip on glass (COG) mounting technology is an example of directly mounting an IC chip for driving a display panel on a substrate of the display panel in an area other than a display area of the display panel via the anisotropic conductive film.
Through the COG mounting technology, in general, a single anisotropic conductive film is disposed between the glass substrate and the IC chip and the IC chip is press-bonded to the glass substrate via the anisotropic conductive film. The anisotropic conductive film includes a thermoset resin as an adhesive. When the anisotropic conductive film shrinks during curing, the IC chip may be pulled toward the glass substrate and warped. A technology for reducing such a warp of the IC chip when the anisotropic conductive film shrinks during curing is disclosed in Patent Document 1.